Introduction:
The P1335 diagnostic trouble code (DTC) indicates a problem within the Crankshaft Position (CKP) sensor circuit. This sensor is crucial for engine timing and performance. A malfunctioning CKP sensor or its circuit can lead to a no-start condition, rough running, or stalling issues.
Table: P1335 - CKP Circuit Information
| Topic | Description | Possible Causes |
|---|---|---|
| CKP Sensor Function | Monitors the crankshaft's position and speed, providing vital data to the Engine Control Module (ECM) for fuel injection and ignition timing. | N/A |
| P1335 Definition | Crankshaft Position (CKP) Sensor A Circuit Malfunction. Indicates an issue with the electrical circuit of the CKP sensor. | Faulty CKP sensor, Damaged wiring or connectors (including open circuits, short circuits, and corrosion), ECM failure (rare), Timing belt/chain issues (e.g., stretched or broken), Excessive crankshaft endplay, Interference from other electrical components, Metal debris interfering with the sensor's magnetic field, Incorrect sensor gap |
| Sensor Types | Magnetic Pickup (Variable Reluctance): Generates an AC voltage signal. Hall Effect: Requires a voltage supply and produces a digital signal. | N/A |
| Symptoms | Engine won't start, Engine stalls, Rough running engine, Check Engine Light (CEL) illuminated, Poor fuel economy, Hesitation or misfires, Loss of power, Erratic tachometer readings. | |
| Testing Procedures | Visual inspection of the sensor and wiring, Multimeter testing for voltage, resistance, and continuity, Oscilloscope testing to analyze the sensor's signal waveform, Scan tool data analysis to monitor CKP sensor readings. | |
| Wiring Diagram Review | Essential for identifying the correct wires to test and the ECM pin locations. | N/A |
| Common Connector Issues | Corrosion, Loose connections, Damaged pins, Moisture intrusion. | N/A |
| Diagnostic Tools | Scan tool (for reading codes and live data), Multimeter (for voltage, resistance, and continuity testing), Oscilloscope (for waveform analysis), Wiring diagrams. | |
| Related Codes | P0335 (CKP Sensor A Circuit), P0336 (CKP Sensor A Circuit Range/Performance), P0337 (CKP Sensor A Circuit Low Input), P0338 (CKP Sensor A Circuit High Input), P0339 (CKP Sensor A Circuit Intermittent). | |
| ECM Role | Receives and interprets the CKP sensor signal, using it to control fuel injection timing, ignition timing, and other engine management functions. | N/A |
| Sensor Location | Typically located near the crankshaft pulley or flywheel. | N/A |
| Signal Interpretation | The ECM uses the CKP signal to determine the exact position of the crankshaft. Any deviation from the expected signal pattern triggers the P1335 code. | N/A |
| Impact of Failure | Engine will likely not start or run properly due to incorrect fuel injection and ignition timing. Potential for engine damage if the timing is significantly off. | N/A |
| Troubleshooting Steps | 1. Visual Inspection: Check for obvious damage to the sensor and wiring. 2. Connector Check: Inspect the connector for corrosion, loose connections, and damaged pins. 3. Wiring Test: Test the wiring for continuity and shorts. 4. Sensor Test: Test the sensor's resistance or voltage output. 5. Signal Check: Use an oscilloscope to verify the sensor's signal waveform. 6. ECM Check: As a last resort, suspect the ECM. | |
| Repair Strategies | Replace the CKP sensor, Repair or replace damaged wiring or connectors, Replace the timing belt/chain, Address excessive crankshaft endplay, Replace the ECM (only after confirming all other possibilities). | |
| Importance of Proper Gap | The air gap between the sensor and the crankshaft reluctor ring (or toothed wheel) must be within the manufacturer's specified range. An incorrect gap can result in a weak or nonexistent signal. | N/A |
| Reluctor Ring Damage | A damaged or missing tooth on the reluctor ring can cause the CKP sensor to generate an inaccurate signal, leading to the P1335 code. | N/A |
Detailed Explanations:
CKP Sensor Function: The Crankshaft Position (CKP) sensor is a critical component of the engine management system. It monitors the position and speed of the crankshaft. This information is relayed to the Engine Control Module (ECM), which uses it to precisely time fuel injection and ignition. Without a properly functioning CKP sensor, the engine cannot operate efficiently or may not start at all.
P1335 Definition: The P1335 code specifically indicates a malfunction within the electrical circuit of the CKP sensor, often referred to as "CKP Sensor A Circuit Malfunction." This means the ECM is detecting an abnormal electrical signal from the sensor circuit, suggesting a problem with the sensor itself, the wiring, or, in rare cases, the ECM. The "A" designation typically refers to the primary CKP sensor in systems with multiple sensors.
Sensor Types: There are two main types of CKP sensors: Magnetic Pickup (Variable Reluctance) and Hall Effect. Magnetic pickup sensors generate an AC voltage signal as the crankshaft rotates. Hall effect sensors require a voltage supply and produce a digital signal (on/off). Knowing the type of sensor your vehicle uses is important for proper testing and diagnosis.
Symptoms: The symptoms of a P1335 code can vary, but common signs include the engine not starting, stalling, rough running, and the Check Engine Light (CEL) illuminating. You might also experience poor fuel economy, hesitation or misfires, loss of power, and erratic tachometer readings. These symptoms occur because the ECM cannot accurately control fuel injection and ignition timing without a reliable CKP sensor signal.
Testing Procedures: Diagnosing a P1335 code involves several steps. Start with a visual inspection of the sensor and its wiring for any obvious damage. Use a multimeter to test the voltage, resistance, and continuity of the wiring. An oscilloscope can be used to analyze the sensor's signal waveform and identify any irregularities. Finally, a scan tool can be used to monitor live data from the CKP sensor.
Wiring Diagram Review: A wiring diagram is essential for troubleshooting electrical problems. It provides a detailed map of the CKP sensor circuit, showing the connections between the sensor, the ECM, and other components. This allows you to identify the correct wires to test and the ECM pin locations. Without a wiring diagram, you're essentially working blind.
Common Connector Issues: Connectors are a common source of problems in electrical circuits. Corrosion, loose connections, damaged pins, and moisture intrusion can all disrupt the flow of electricity. Carefully inspect the CKP sensor connector for any of these issues. Cleaning corroded terminals and ensuring a secure connection can often resolve the P1335 code.
Diagnostic Tools: Several tools are helpful for diagnosing a P1335 code. A scan tool is used to read the DTCs and monitor live data. A multimeter is used to measure voltage, resistance, and continuity. An oscilloscope is used to analyze the sensor's signal waveform. Wiring diagrams are essential for understanding the circuit layout.
Related Codes: The P1335 code is often accompanied by other related codes, such as P0335 (CKP Sensor A Circuit), P0336 (CKP Sensor A Circuit Range/Performance), P0337 (CKP Sensor A Circuit Low Input), P0338 (CKP Sensor A Circuit High Input), and P0339 (CKP Sensor A Circuit Intermittent). These codes provide more specific information about the nature of the problem.
ECM Role: The Engine Control Module (ECM) is the brain of the engine management system. It receives and interprets the CKP sensor signal, using it to control fuel injection timing, ignition timing, and other engine management functions. A faulty ECM can sometimes trigger the P1335 code, but this is relatively rare.
Sensor Location: The CKP sensor is typically located near the crankshaft pulley or flywheel. Its exact location varies depending on the vehicle make and model. It's usually mounted in a position where it can sense the teeth of a reluctor ring or toothed wheel on the crankshaft.
Signal Interpretation: The ECM uses the CKP signal to determine the exact position of the crankshaft at any given moment. This information is critical for precise fuel injection and ignition timing. Any deviation from the expected signal pattern, such as a missing pulse or an incorrect frequency, can trigger the P1335 code.
Impact of Failure: If the CKP sensor fails, the engine will likely not start or run properly because the ECM cannot accurately control fuel injection and ignition timing. In severe cases, a malfunctioning CKP sensor can even lead to engine damage if the timing is significantly off.
Troubleshooting Steps:
- Visual Inspection: Begin by visually inspecting the CKP sensor and its wiring for any signs of damage, such as cracks, breaks, or corrosion.
- Connector Check: Carefully inspect the connector for corrosion, loose connections, and damaged pins. Clean any corroded terminals and ensure a secure connection.
- Wiring Test: Use a multimeter to test the wiring for continuity and shorts. Check for open circuits and shorts to ground or power.
- Sensor Test: Test the sensor's resistance or voltage output according to the manufacturer's specifications. This will help determine if the sensor itself is faulty.
- Signal Check: Use an oscilloscope to verify the sensor's signal waveform. Look for any irregularities in the signal pattern.
- ECM Check: As a last resort, suspect the ECM. However, this should only be done after confirming that all other components are functioning properly.
Repair Strategies: Based on the troubleshooting results, the following repair strategies may be necessary:
- Replace the CKP sensor: If the sensor is found to be faulty, replacing it is the most common solution.
- Repair or replace damaged wiring or connectors: If the wiring or connectors are damaged, repair or replace them as needed.
- Replace the timing belt/chain: If the timing belt or chain is stretched or broken, it needs to be replaced.
- Address excessive crankshaft endplay: Excessive crankshaft endplay can cause the CKP sensor to generate an inaccurate signal.
- Replace the ECM: Only replace the ECM after confirming that all other possibilities have been ruled out.
Importance of Proper Gap: The air gap between the sensor and the crankshaft reluctor ring (or toothed wheel) must be within the manufacturer's specified range. An incorrect gap can result in a weak or nonexistent signal, triggering the P1335 code. Use a non-ferrous feeler gauge to measure the gap and adjust it as necessary.
Reluctor Ring Damage: A damaged or missing tooth on the reluctor ring can cause the CKP sensor to generate an inaccurate signal, leading to the P1335 code. Carefully inspect the reluctor ring for any damage. If damage is found, the reluctor ring must be repaired or replaced.
Frequently Asked Questions:
- What does the P1335 code mean? It indicates a malfunction in the Crankshaft Position (CKP) sensor circuit. This typically involves a problem with the sensor, wiring, or ECM.
- Can I drive with a P1335 code? It's not recommended. The engine may stall, run poorly, or not start at all, posing a safety risk.
- How do I fix a P1335 code? Diagnose the problem using a multimeter and oscilloscope, then repair or replace the faulty component, such as the sensor or wiring.
- Is the CKP sensor easy to replace? It depends on the vehicle. Some are easily accessible, while others require more extensive disassembly.
- Can a bad timing belt cause a P1335 code? Yes, a stretched or broken timing belt can affect the crankshaft's position, leading to an inaccurate CKP sensor signal.
Conclusion:
The P1335 code signifies a problem within the CKP sensor circuit, which is vital for engine operation. Thoroughly diagnose the circuit using the steps outlined in this article and address the root cause to restore proper engine function. Ignoring this issue can lead to further engine damage and safety concerns.